The present invention relates to electrical connectors and sensors useful in many applications, but particularly intended for use in hostile environments. More specifically, the present invention relates to single and multi-pin electrical connectors and sensors for use in high-pressure, high-temperature applications which commonly occur in the oilfield, but which are also encountered in geothermal and research applications.
Oil wells are being drilled to deeper depths and encountering harsher conditions than in the past. Many of the electrical connectors in the oilfield are exposed to the environment of the open well bore, where at maximum depth, pressures rise to over 30,000 psig, temperatures exceed 500 degrees, F, and the natural or chemically-enhanced well bore environment is extremely corrosive.
There have been many attempts made in the prior art to design, manufacture and market electrical connectors for use in such hostile environments, some of which have met with more success than others. For example, U.S. Pat. No. 6,582,251 to Burke et al, describes an “all plastic” body connector, i.e., all plastic other than for the metal conductor pin and the threaded metal body, in which the metal conductor pin is embedded in a molded body formed from polyetherketone (PEK), or other polymeric materials such as ULTEM, PAEK, PEEK or PEKK. When used with a threaded metal body, the plastic body will oftentimes extrude away from the metal conductor pin, causing the conductor pin to contact the metal body, causing immediate failure. At temperatures and pressures approaching 500° F. and 30,000 psi, respectively, the extrusion can be so severe that fluids leak between the conductor and the threaded metal body and flood the very instrument the connector was intended to protect.
The all plastic connector, even when not used with a metal body, will oftentimes fail, based upon the extrusion of the plastic in the instrument gland may cause the conductor pin to move so much that the connection to the boot is lost. In extreme cases the extrusions give rise to a hydraulic failure due to deformation of the o-ring gland of the connector to the point that the seal is no longer effective.
In addition to the all plastic connector, the prior art also includes U.S. Pat. Nos. 3,793,608 and 3,898,731, each to Sandiford Ring and Russell K. Ring, which disclose electrical connectors which operate quite well in harsh environmental such as very hot, very deep, high pressure wells, in which such connectors use glass seals in combination with ceramic seals.
In addition, U.S. Pat. No. 7,364,451 to John H. Ring and Russell K. Ring discloses an electrical connector for use in very hot, high pressure wells using, in combination, glass seals, ceramic seals, a plastic body molded, for example, from aromatic polyetherketones or other thermoplastic materials and in some embodiments, includes a thermoplastic jacket made from PAEK, PEEK, PEK and PEKK, or the like.
However, even with all the success experienced by the electrical connectors using glass seals in combination with ceramic seals, it should be appreciated that glass seals are relatively expensive. There thus exists a need for electrical conductors in high pressure, high temperature wells without the use of glass seals. The electrical connectors of the present invention provides some of the high pressure, high temperature capabilities of the hybrid type of connectors, but having manufacturing costs quite similar to the all plastic versions of electrical connectors of the prior art.